The present invention relates to a headlight arrangement for a motor vehicle.
More particularly, it relates to such a headlight arrangement which has a reflector subdivided into several reflector regions, a light source arranged in the region of the apex of the reflector, so that light which is emitted by the light source is reflected by the reflector on a roadway in front of the motor vehicle, and at least one screening device associated with at least one selected reflector region. The screening device is adjustable between a passage position in which the light emitted by the light source can reach the selected reflector region, and a screening position in which it screens the reflector region from the light emitted by the light source.
In such headlight arrangements, the reflector can be subdivided however into several desired functional reflector regions. The subdivision must not be visible from outside, for example as steps between the reflector regions. Such headlight arrangement is disclosed for example in the German patent document DE 43 07 110 A1. The lateral reflector regions of the open headlight arrangement disclosed in this reference influence the side dispersion, the upper and lower reflector region influence the pre-field illumination.
For switching of the known headlight arrangement from the right side traffic to the left side traffic and vice versa, the headlight arrangement is provided with at least one screening device which screens the lateral reflector regions from the light source so that an asymetric illumination intensity distribution is produced with the bright-dark limit increasing toward the roadway edge at the road side itself (in other words right for the right side traffic and left for the left side traffic).
While the screening devices in accordance with the prior art can be switched between the passage position and the screening position, an intermediate position is not provided in them. The screening device disclosed in the German patent document DE 43 07 110 A1 can be switched between the two positions for the right side traffic and left side traffic. The headlight arrangement has the same statistic light distribution for the right side traffic and the left side traffic. However, for an asymmetrical illumination intensity distribution the bright-dark limit at the roadway side raising toward the roadway edge can be switched for the right side traffic to the right and for the left side traffic to the left.
It has been however recognized that there is no optimal statistic illumination which can be correct for all road and traffic situations. For example, during driving on a speedway with a high speed another optimal light distribution is required by governmental regulations that during driving with a lower speed. Therefore, a headlight arrangement would be desirable, in which the light distribution can be controlled adaptively, or in other words in correspondence with the road and traffic situations.
A so-called curve headlight is known from the prior art and has turnable reflectors for variation of the dispersion width. With such a curve headlight the roadway edges during driving over curves can be illuminated wider. Moreover, free-standing individual headlights are known, which are arranged at the right side and the left side of the motor vehicle and provide illumination in the side regions. By turning on and turning off of the individual headlights, the side width of the vehicle can be illuminated as desired.
In the known curve headlights disclosed in the prior art, the construction is substantially large because of the adjustment mechanism and the turnable reflectors. Moreover they take into consideration only the steering angle as a single control value for the light distribution. Finally, the turnable reflectors are subjected to wear and must be maintained in regular time intervals. Due to the turnable reflectors and the broadly fluctuating environmental conditions (temperature, air moisture, dirt) in the headlights, the known curve headlight is especially sensitive.
The lateral single headlights in accordance with the prior art has a disadvantage that they are fixedly mounted on the motor vehicle. They have no flexibility with regard to the light distribution. They are either turned on and illuminate the side regions or they are turned off and do not illuminate the side regions. Intermediate positions which can be desirable for illumination of only predetermined parts of the side regions for illumination of side regions with variable intensity, are not provided. The known single headlights require a mounting space in the motor vehicle.